Road machine



J ly 30, 1929- D. WHEELER 1,722,725

ROAD MACHINE;

Filed Aug. 11, 1927 2 Sheets-Sheet 1 Poo wuniumlmlmrn I gwumtoz July 30, 1929. WHEELER 1,722,725

4 ROAD MACHINE Filed Aug 11, 1927 2 Sheets-Sheet 2 Patented July 30, 1929.

warren stares DELBERT WHEELER, OF SIOUX FALLS, SOUTH DAKOTA.

ROAD MACHINE.

Application filed August 11, 1927.

My invention relates to road machines, and has for its object to provide primarily a road maintaining and surfacing machine, which may be used upon roads having either soft surfaces, such as dirt, clay, sand and the like, or those having semi-hard surfaces, such as gravel, old macadam, etc.

My invention involves the use of a cutter of the rotary type and it is my purpose to provide a machine in which a single rotary cutter combines the function of scraping and cutting with that of conveying thedirt to till the low spots and to bring the surface to the proper grade.

I am aware that the rotary screw has before been used in connection with road machinery. Inmost cases, a rotating screw has been employed to convey material laterally and has comprised ordinarily a single blade screw, or a screw having a relatively low pitch so that the scraping action of the blade against the road bed will be largely in a direction transverse to that in which the machine is moving. In most cases, such rotary conveyors are used in connection with straight blades or other devices for loosening the material from the road bed and act principally as conveyors. In fulfilling my object of providing a cutter to act both as a conveyor and cutter,

have pitch angles of relatively large magnitude, (somewhere approximately I find that such a cutter accomplishes several desirable objects. In the first place, and most important, each blade is presented to the road at an angle of approximately 45 to the line of travel to the machine, and when rotated oppositely to the direction of rotation of the wheels of the machine, will obtain a cross between a shear and a sliced out. At the same time, the rotation of the cutter will throw the'material both in a forward and a lateral direction so as'to reduce the tendency of the material to resist forward movement oft-he cutter and to convey the material to the low spots where it may be deposited. Another result that is had is the production of a practically straight out in a direction transverse of the roadway without the necessity of revolving the cutter at a very high rate of speed, that is, the surface of the road bed will be left smooth and free from ridges running longitudinally of the roadway.

I utilize a plurality'of helical blades which Serial No. 212,291.

An object of my invention has been to combine the features of moving material forwardly and obtaining a shearing cut without ridging effects with that of the lateral conveying of material so as to more efficiently fill all those spots in such a manner as to obtain the highest elficiency in each function.

'VVith these and other objects in View my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth. pointed out in my claims, and illustrated in the accompanying drawings, in which:

Fig. 1 is a plan View of a road machine embodying my invention.

Fig. 2 is a right side elevation of the same.

Fig. 3 is a transverse, sectional view of the same, taken on the line 33 of Fig. 2.

Fig. l a detail, sectional view taken on the line 4-t of Fig. 1.

Fig. 5 is a detail, sectional view taken transversely through-the cutter.

Fig. 6 is a detail, sectional view taken on the line 6-6 of Fig. 1.

Fig. 7 is a detail, sectional view taken on the line 77 of Fig. 3.

In the accompanying drawings, I have shown in a general way the frame of a road machine which may comprise the longitudinal members 10, the front cross members 11, the intermediate cross member 12 and the rear cross member 13, all connected by gusset plates 14: or the like.

An inner frame is formed between the cross members 12 and-13 and the auxiliary, longitudinal frame members 15, which are secured thereto and extend therebetween in positions spaced inwardly from the longitudinal members 10. In the spaces thus formed, the cut ter suspending mechanism, which will later be described, is received.

The frame is supported upon rearward and forward travel wheels 16 and 17, respectively.

The cutter is of the rotary type, as has al-v ready been stated, and comprises a cylinder 18, mounted upon a shaft 19 by means of spiders or the like 20 at the ends of the cylin der. The cutting blades 21 are L shaped in cross section, the shorter. arms 22 of the blades being secured to the cylinder 18 by riveting,

bolting, or the like.

Although I have shown eight of the cutter blades, a lesser or greater number may be employed. It will be understood, however, that one feature of my invention necessitates the use of a plurality of blades and a number the blades will have moved less than four will probably not be successful in accomplishing the result which I seek to obtain. :As many more than eight blades may be used, up to a point where the close proximity of the blades Wlll interfere with the. bite which any one blade can procure against the surface of a road bed. For this reason, the limits between which my invention can'be most successfully practiced will be from six to twelve blades. In employment of eight blades, as shown in Fig. 5, the blades are set at an angle of approximately fortyfive degrees to the axis of the cylinder 18 and will be spaced apart substantially as shown in Fig. 8. v

It may now be noted that a cross-section through a cut produced by moving the cutter in a direction transverse to its axis will be very nearly straight, the ridges between the blades being comparatively shallow. It may be noted further that by rotation of the cutter,

in a direction reverse to that of the rotation of the wheels; through an eighth. of revolution, the position of one blade will shift to that of the adjacent blade and consequentl 1 if the cutter is revolving at a rate of one revolution per second, any particular point in the path of the cutter blades will be scraped by eight of the blades each second. Assuming the cutter to be geared directly to a small gasoline engine having a normal speed of approximately 600 R. P. M; and geared down so as to turn about one-fourth as fast as'the engine, it will receive power at the rate of approximately 1.50 R. P. M. or two and one-half revolutions per second. At this rate, a par ticular point in the roadway will be subjected to approximately twenty blade contacts per second.

The normal speed of a road machine in a forward direction might be taken as approximately two feet per second. Thus in a distance of two feet forward travel, a particular line parallel to the direction of travel will have been crossed by some blade twenty times and in a'distance of approximately an inch and a half of forward travel, one of so as to take the position of the adjacent blade.

It will be seen from this that the cutter may be rotated at a very reasonable rate of speed and yet the road machine moved ahead at the normal rate without producing longitudinal ridges in the road from the curved edges of the blades. The surface left i by the cutter will be absolutely straight in en cross-section. p

Theinelination of the blades is such that there will be a tendency to carry the material, which is scraped from the road. bed, in a lateral direction.

It may be noted at this point,however, that eflicient in loosening packed or gravelled road without producing meek a5 it is undesirable to exaggerate "this lateral conveying function of the cutter. It will be remembered at this point that the primary purpose of my invention is to provide a road-maintaining machine and that I do not wish to transport material beyond the inner end of the cutter any more than will result of necessity. In road maintenance, the grade of the road bed has been definitely established and the only cutting that is necessary is for the purpose of reducing the slight elevations which have formed and depositing the material scraped from these elevations into the adjacent depressions. In the ordinary gravel road, there is a tendency for the road bed to assume what is known as the wash board effect, in which parallel ridges are formed, extending transversely of the road. The cause of this condition proceeds from the fact that the springs in most cars are tuned so as to respond to similar vibration periods and the consequent regular jumping of the wheels tends to increase the depth of the regularly produced depressions.

It will now be seen that in order to most efliciently reduce these transverse ridges, the proper method is to deposit the material from one ridge in a substantially forward direction to the adjacent depression. To carry the material laterally, a disproportionate distance would be to increase the amount of power needed by the cutter.

The ordinary single blade scraper that is used in prevailing types of road machines to day, however, has the disadvantage that it moves against the road bed only as fastas the machine can move forwardly. By rotating the blade and thereby giving it a motion independent ofthe motion of the carriage structure of the maehine, it may be moved against,

the roadway at a much faster ratethan the forward travel of the machine and instead of forcing a single blade to its full depth of out without any preliminary removal of material, the curved cross-section of the rotary cutter obtains a cut in which the depth varies from the forward edge of the cutter, where it is zero, to the rear extremity of the out directly below the axisofthe cutter where it is at its maximum.

A trueplaning effectis thus obtained, as contrasted with the scraping effect of the straight blade;

Another advantage over the straight blade lies in the fact that a more slicing out can be obtained by the blades which are set at an angle of forty-five degrees as compared with the usual angle of less than thirty degrees for a straight blade. The cut of the blades of my rotaryicutter is a cross between a pure slicing cut and a strictly shear out and is most the surface of a hardtoo much friction therewith. In order to 0bprobably tain such a slicing shear with a straight blade, it would be necessary to employ a blade which would be prohibitively long in order to also cover the proper width of the out.

Returning now to a consideration of the relation between lateral conveying and forward movement of the material, it will be seen that the angle of the blades is such that the tendency to throw the material forward will be as great, if not greater, than the tendency to convey it laterally. As a matter of fact, in actual practice, the tendency to throw the material forwardly is much greater than the lateral conveying tendency, for the reason that the blades are rotating in a forward direction and all friction between the sharp, gravelled articles and the blade will result in a tendency to give the gravel particles a forward motion, whereas, in order to move laterally, they must slide relative to the blade.

The combination of the tendency to throw material forwardly and of the tendency to convey it laterally, results in the following: l/V here a road bed is encountered with welldefined transverse ridges, the effect of the cutter is to throw the material forwardly from a ridge to the next adjacent depression where a road is encountered in which the ridges run more longitudinally than transversely, the effeet will be mainly to throw the material laterally. This follows from the fact that the gravel will follow the course of least resistance and the rotating cutter exerts a push in both directions.

This effect differs from that of a straight blade in that in the straight blade, due to its much slower speed, there is a tendency for the gravel to pile up in front of the blade and where the gravel mustmove any considerable distance from the point where it has been removed to the depression to be filled, its resistance to such movement will be so great that the blade will pass over i before it has reached the point of deposit.

The cutter is suspended from the frame of the vehicle by means of a carriage bar 3, to which is secured a pair of steel spring arms 24, pivoted upon a shaft 25. The arms 24 rigidly position the carriage bar 23 against twisting from its proper horizontal position and serve also as draw bars. The weight of the carriage bar 23 is supported by adjustable mechanism including links 26, pivoted in eye bolts 27, which serve to partly secure the arms 24 to the carriage bar, the upper ends of the links 26 being suspended from levers 28, secured to gears 29 upon stub shafts 30, jour nalled in bearings 31 and 32, supportedupon the longitudinal members 10 and 15, respectively. The gears 29 mesh with pinions 33, which are mounted on shafts 34, ournalled in the same bearings 31 and 32 and provided with hand wheels 35. It will now be seen that by rotation of the hand wheels 35, the lever arms 28 may be raised or lowered to raise or lower either end of the carriage bar 23. In thus raising or lowering the carriage bar, the twisting tendency produced will be compensated by the resiliency of the arms 24. The twisting tendency-of the arms 24 themselves is compensated by forming the openings 36 in the ends of the arms of hyperboloid crosssection, as shown in Fig; 6.

Power from an internal combustion engine or the like 37 is transmittedfrom a drive pinion 38 on the engine crank shaft to a bevel gear 39 on a shaft 40, which is mounted in a bracket 41, carried by the plate 42 which supports the engine 37. The plate 42 is supported between the auxiliary frame members 15. A universal joint 43 connects the shaft with an intermediate shaft 44, which is provided with an internally squared sleeve 45 to receive a squared shaft 46. The shaft 46' is in turn connected by means of a universal joint 47 to a lower shaft 48, which is journalled in a bracket 49, mounted on the carriage bar .23.

The lower end of the shaft 48 carries a bevel gear 50, which drives a bevel gear 51 on the shaft 19 of the cutter. The cutter shaft is It will now be seen that adjustment of-the supporting mechanism vertically may be employed to tilt the cutter laterally, for instance, by raising one end of the cutter bar, that end of the cutter may be tilted upwardly. It will be understood, however, that the cutter will never be tilted any great extent, since the machine is intended for maintaining roads in which the grade is already established.

' Tilting of the cutter is taken care of by the universal connections 43 and 47 and the sliding connection of the shaft 46 with the sleeve 45 so that such tilting will not interfere with the drive from the engine.

It may be noted further that the suspension of the cutter is practically a floating suspension so that should any obstacles beencountered in the path of the cutter, which are of such nature that the cutter cannot remove them, it may ride over such obstacles.

Some changes may be made in the construction and arrangement of the parts of my invention without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modiiied forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a road machine, a carriage having travel wheels, a cutter rotatably mounted in the carriage, said cutter comprising a plurality of helical blades mounted at an angle of between forty and SiXty degrees to the cutter axis, and means for rotating the cutter in a direction opposite to the direction of rotation of the travel Wheels at a rate that is several times faster than the rate of revolution of the travel Wheels during normal travel, the parts being so arranged that the cutter Will serve the three purposes of planing a road bed Without leaving noticeable longitudinal ridges therein, of conveying material laterally, and of throwing material for- Wardly.

2. In a road machine, a carriage having travel Wheels, a cutter rotatably mounted in the carriage, said cutter comprising a plurality of helical blades mounted at an angle of between forty and sixty degrees to the cutter axis, and means for rotating the cutter in a direction opposite to the direction of rotation of. the travel Wheels at a rate of at least one revolution per second, the parts being so arranged'that the cutter Will serve the three purposes of planing a road bed Without leaving noticeable longitudinal ridges therein,

of conveying material laterally, and of throwing material forwardly.

' 3. In a road machine, a carriage having travel Wheels, a cutter mounted in the carriage for rotation about an axis that is substantially at right angles to the direction of travel of the machine, said cutter comprising a plurality. of helical blades mounted at an angle of between forty and sixty degrees to leaving noticeable longitudinal ridges therei in, of conveying material laterally, and of throwing material iorvvardly.

4. In a road machine, a carriage having travel Wheels, a cutter mounted in the carriage for rotation about an axis that is substantiallyat right angles to the direction of travel of the machine, said cutter comprising at least four helical blades mounted at an angle of between forty and sixty degrees to the cutter axis, and means for rotating the cutter in a direction opposite to the direction of rotation of the travel Wheels at a rate of at least one revolution per second, the parts being so arranged that the cutter'Will serve the three purposes of planing a road bed Without leaving noticeable longitudinal ridges therein, of. conveying material laterally, and of throwing material forwardly.

Signed this 27 day of July, 1927, in the county of Minnehaha and State of South. Dakota. v

DELBERT WHEELER. 

